Re: [PATCH V2 2/3] powerpc: Add support for swiotlb on 32-bit
From: Becky Bruce
Date: Wed May 27 2009 - 15:05:53 EST
On May 22, 2009, at 6:11 AM, Ian Campbell wrote:
BTW do you need swiotlb_bus_to_virt to be __weak or is the fact that
it
is implemented in terms of swiotlb_bus_to_phys sufficient?
The default one in swiotlb calls phys_to_virt on the result of
swiotlb_bus_to_phys, which only works on lowmem.
I have an appointment all afternoon and it's a bank holiday on Monday
but here is my WIP patch as an example of what I'm thinking. Obviously
some cleanups are still very much required:
* The Xen specific stuff in arch/x86/include/asm/dma-mapping.h
clearly needs to be properly abstracted away (I just stuck it
there for testing).
* swiotlb_phys_to_bus and swiotlb_bus_to_phys need to move to
arch/*/include/asm/dma-mapping.h instead of being __weak
* Maybe swiotlb_bus_to_virt can become static again.
* Need to finish auditing the handful of non-swiotlb users of
is_buffer_dma_capable.
* It might be possible to implement swiolb_dma_mapping_error
and/or swiotlb_dma_supported in terms of dma_map_range.
* Minor detail: it doesn't actually work at the moment ;-)
Minor detail :)
I'm in the same boat- been offline most of the week and will continue
to be offline (I'm sneaking in an hour here to read emails!!!!) until
sometime next week. I'm in the middle of a big lab construction and
move project. I'll take a look as soon as I can - thanks!
-Becky
Ian.
diff --git a/arch/ia64/include/asm/dma-mapping.h b/arch/ia64/include/
asm/dma-mapping.h
index 36c0009..026667f 100644
--- a/arch/ia64/include/asm/dma-mapping.h
+++ b/arch/ia64/include/asm/dma-mapping.h
@@ -174,4 +174,12 @@ dma_cache_sync (struct device *dev, void
*vaddr, size_t size,
#define dma_is_consistent(d, h) (1) /* all we do is coherent
memory... */
+static inline dma_addr_t dma_map_range(struct device *dev, u64 mask,
+ phys_addr_t addr, size_t size)
+{
+ if (addr + size <= mask)
+ return addr;
+ return 0;
+}
+
#endif /* _ASM_IA64_DMA_MAPPING_H */
diff --git a/arch/x86/include/asm/dma-mapping.h b/arch/x86/include/
asm/dma-mapping.h
index 916cbb6..b2813ab 100644
--- a/arch/x86/include/asm/dma-mapping.h
+++ b/arch/x86/include/asm/dma-mapping.h
@@ -309,4 +309,20 @@ static inline void dma_free_coherent(struct
device *dev, size_t size,
ops->free_coherent(dev, size, vaddr, bus);
}
+static inline dma_addr_t dma_map_range(struct device *dev, u64 mask,
+ phys_addr_t addr, size_t size)
+{
+ dma_addr_t dma_addr;
+#ifdef CONFIG_XEN
+ extern int xen_range_needs_mapping(phys_addr_t paddr, size_t size);
+ if (xen_pv_domain() && xen_range_needs_mapping(addr, size))
+ return 0;
+#endif
+
+ dma_addr = swiotlb_phys_to_bus(dev, addr);
+ if (dma_addr + size <= mask)
+ return 0;
+ return dma_addr;
+}
+
#endif
diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index 2fffc22..c2b4196 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -145,8 +145,8 @@ again:
if (!page)
return NULL;
- addr = page_to_phys(page);
- if (!is_buffer_dma_capable(dma_mask, addr, size)) {
+ addr = dma_map_range(dev, dma_mask, page_to_phys(page), size);
+ if (!(addr == 0)) {
__free_pages(page, get_order(size));
if (dma_mask < DMA_BIT_MASK(32) && !(flag & GFP_DMA)) {
diff --git a/arch/x86/kernel/pci-gart_64.c b/arch/x86/kernel/pci-
gart_64.c
index 1e8920d..6a55770 100644
--- a/arch/x86/kernel/pci-gart_64.c
+++ b/arch/x86/kernel/pci-gart_64.c
@@ -191,13 +191,13 @@ static inline int
need_iommu(struct device *dev, unsigned long addr, size_t size)
{
return force_iommu ||
- !is_buffer_dma_capable(*dev->dma_mask, addr, size);
+ dma_map_range(dev, *dev->dma_mask, addr, size) == 0;
}
static inline int
nonforced_iommu(struct device *dev, unsigned long addr, size_t size)
{
- return !is_buffer_dma_capable(*dev->dma_mask, addr, size);
+ return dma_map_range(dev, *dev->dma_mask, addr, size) == 0;
}
/* Map a single continuous physical area into the IOMMU.
diff --git a/arch/x86/kernel/pci-nommu.c b/arch/x86/kernel/pci-nommu.c
index 71d412a..712ce59 100644
--- a/arch/x86/kernel/pci-nommu.c
+++ b/arch/x86/kernel/pci-nommu.c
@@ -12,13 +12,13 @@
#include <asm/dma.h>
static int
-check_addr(char *name, struct device *hwdev, dma_addr_t bus, size_t
size)
+check_addr(char *name, struct device *hwdev, phys_addr_t phys,
size_t size)
{
- if (hwdev && !is_buffer_dma_capable(*hwdev->dma_mask, bus, size)) {
+ if (hwdev && dma_map_range(hwdev, *hwdev->dma_mask, phys, size) ==
0) {
if (*hwdev->dma_mask >= DMA_BIT_MASK(32))
printk(KERN_ERR
"nommu_%s: overflow %Lx+%zu of device mask %Lx\n",
- name, (long long)bus, size,
+ name, (long long)phys, size,
(long long)*hwdev->dma_mask);
return 0;
}
@@ -30,12 +30,12 @@ static dma_addr_t nommu_map_page(struct device
*dev, struct page *page,
enum dma_data_direction dir,
struct dma_attrs *attrs)
{
- dma_addr_t bus = page_to_phys(page) + offset;
+ phys_addr_t phys = page_to_phys(page) + offset;
WARN_ON(size == 0);
- if (!check_addr("map_single", dev, bus, size))
+ if (!check_addr("map_single", dev, phys, size))
return bad_dma_address;
flush_write_buffers();
- return bus;
+ return phys;
}
/* Map a set of buffers described by scatterlist in streaming
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 8083b6a..85dafa1 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -96,11 +96,6 @@ static inline int is_device_dma_capable(struct
device *dev)
return dev->dma_mask != NULL && *dev->dma_mask != DMA_MASK_NONE;
}
-static inline int is_buffer_dma_capable(u64 mask, dma_addr_t addr,
size_t size)
-{
- return addr + size <= mask;
-}
-
#ifdef CONFIG_HAS_DMA
#include <asm/dma-mapping.h>
#else
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index cec5f62..4fd5185 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -147,17 +147,6 @@ void * __weak swiotlb_bus_to_virt(struct device
*hwdev, dma_addr_t address)
return phys_to_virt(swiotlb_bus_to_phys(hwdev, address));
}
-int __weak swiotlb_arch_address_needs_mapping(struct device *hwdev,
- dma_addr_t addr, size_t size)
-{
- return !is_buffer_dma_capable(dma_get_mask(hwdev), addr, size);
-}
-
-int __weak swiotlb_arch_range_needs_mapping(phys_addr_t paddr,
size_t size)
-{
- return 0;
-}
-
static void swiotlb_print_info(unsigned long bytes)
{
phys_addr_t pstart, pend;
@@ -318,17 +307,6 @@ cleanup1:
return -ENOMEM;
}
-static inline int
-address_needs_mapping(struct device *hwdev, dma_addr_t addr, size_t
size)
-{
- return swiotlb_arch_address_needs_mapping(hwdev, addr, size);
-}
-
-static inline int range_needs_mapping(phys_addr_t paddr, size_t size)
-{
- return swiotlb_force || swiotlb_arch_range_needs_mapping(paddr,
size);
-}
-
static int is_swiotlb_buffer(char *addr)
{
return addr >= io_tlb_start && addr < io_tlb_end;
@@ -555,18 +533,17 @@ void *
swiotlb_alloc_coherent(struct device *hwdev, size_t size,
dma_addr_t *dma_handle, gfp_t flags)
{
- dma_addr_t dev_addr;
+ phys_addr_t phys;
void *ret;
int order = get_order(size);
u64 dma_mask = DMA_BIT_MASK(32);
+ dma_addr_t dma_addr;
if (hwdev && hwdev->coherent_dma_mask)
dma_mask = hwdev->coherent_dma_mask;
ret = (void *)__get_free_pages(flags, order);
- if (ret &&
- !is_buffer_dma_capable(dma_mask, swiotlb_virt_to_bus(hwdev,
ret),
- size)) {
+ if (ret && dma_map_range(hwdev, dma_mask, virt_to_phys(ret), size)
== 0) {
/*
* The allocated memory isn't reachable by the device.
*/
@@ -585,19 +562,20 @@ swiotlb_alloc_coherent(struct device *hwdev,
size_t size,
}
memset(ret, 0, size);
- dev_addr = swiotlb_virt_to_bus(hwdev, ret);
+ phys = virt_to_phys(ret);
/* Confirm address can be DMA'd by device */
- if (!is_buffer_dma_capable(dma_mask, dev_addr, size)) {
- printk("hwdev DMA mask = 0x%016Lx, dev_addr = 0x%016Lx\n",
+ dma_addr = dma_map_range(hwdev, dma_mask, phys, size);
+ if (dma_addr == 0) {
+ printk("hwdev DMA mask = 0x%016Lx, physical addr = 0x%016Lx\n",
(unsigned long long)dma_mask,
- (unsigned long long)dev_addr);
+ (unsigned long long)phys);
/* DMA_TO_DEVICE to avoid memcpy in unmap_single */
do_unmap_single(hwdev, ret, size, DMA_TO_DEVICE);
return NULL;
}
- *dma_handle = dev_addr;
+ *dma_handle = dma_addr;
return ret;
}
EXPORT_SYMBOL(swiotlb_alloc_coherent);
@@ -649,7 +627,7 @@ dma_addr_t swiotlb_map_page(struct device *dev,
struct page *page,
struct dma_attrs *attrs)
{
phys_addr_t phys = page_to_phys(page) + offset;
- dma_addr_t dev_addr = swiotlb_phys_to_bus(dev, phys);
+ dma_addr_t dma_addr;
void *map;
BUG_ON(dir == DMA_NONE);
@@ -658,9 +636,9 @@ dma_addr_t swiotlb_map_page(struct device *dev,
struct page *page,
* we can safely return the device addr and not worry about bounce
* buffering it.
*/
- if (!address_needs_mapping(dev, dev_addr, size) &&
- !range_needs_mapping(phys, size))
- return dev_addr;
+ dma_addr = dma_map_range(dev, dma_get_mask(dev), phys, size);
+ if (dma_addr && !swiotlb_force)
+ return dma_addr;
/*
* Oh well, have to allocate and map a bounce buffer.
@@ -671,15 +649,14 @@ dma_addr_t swiotlb_map_page(struct device
*dev, struct page *page,
map = io_tlb_overflow_buffer;
}
- dev_addr = swiotlb_virt_to_bus(dev, map);
-
/*
* Ensure that the address returned is DMA'ble
*/
- if (address_needs_mapping(dev, dev_addr, size))
+ dma_addr = dma_map_range(dev, dma_get_mask(dev),
virt_to_phys(map), size);
+ if (dma_addr == 0)
panic("map_single: bounce buffer is not DMA'ble");
- return dev_addr;
+ return dma_addr;
}
EXPORT_SYMBOL_GPL(swiotlb_map_page);
@@ -820,10 +797,8 @@ swiotlb_map_sg_attrs(struct device *hwdev,
struct scatterlist *sgl, int nelems,
for_each_sg(sgl, sg, nelems, i) {
phys_addr_t paddr = sg_phys(sg);
- dma_addr_t dev_addr = swiotlb_phys_to_bus(hwdev, paddr);
-
- if (range_needs_mapping(paddr, sg->length) ||
- address_needs_mapping(hwdev, dev_addr, sg->length)) {
+ dma_addr_t dma_addr = dma_map_range(hwdev, dma_get_mask(hwdev),
paddr, sg->length);
+ if (dma_addr == 0 || swiotlb_force) {
void *map = map_single(hwdev, sg_phys(sg),
sg->length, dir);
if (!map) {
@@ -835,9 +810,9 @@ swiotlb_map_sg_attrs(struct device *hwdev,
struct scatterlist *sgl, int nelems,
sgl[0].dma_length = 0;
return 0;
}
- sg->dma_address = swiotlb_virt_to_bus(hwdev, map);
- } else
- sg->dma_address = dev_addr;
+ dma_addr = dma_map_range(hwdev, dma_get_mask(hwdev),
virt_to_phys(map), sg->length);
+ }
+ sg->dma_address = dma_addr;
sg->dma_length = sg->length;
}
return nelems;
--
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